I’ve got HA with Frigate + USB Coral w/4 cams, FlightRadar24 receiver/feeder, ESPHome, NodeRed, InfluxDB, Mosquitto, and Zwave-JS on a refurbished Lenovo ThinkCenter M92p Tiny, rigged with an i5 3.6GHz, 8GB RAM and 500GB spindle drive. It’s almost overkill.
Frigate monitors 2 RTSP and 2 MJPEG cams (sometimes up to 3 RTSP and 5 MJPEG, depending of if I’m away for the weekend) with hardware video conversion. FR24 monitors a USB SDR dongle tracking several hundred aircraft per hour. I live under one.of the main approaches to a major US hub.
Processor sits at 10% or less most of the time, and really only spikes when I compile new binaries for the ESP32 widgets I have around the house. It uses virtually none of the available disk. It’s an awesome platform for HA for the price.